With an increasing demand for power density and efficiency of a power converter, an existing technology may not meet the demand since there is not a breakthrough in a converter topology technology.
A single power converter adopts a two-stage structure. A power factor correction (PFC) unit implements a pre-regulated voltage for alternating current-direct current (AC-DC). A DC-DC conversion unit converts the pre-regulated voltage into a required output voltage. In this way, a stress of a switching device is relatively high, and a volume of a magnetic device is large as well, resulting in no advantage in terms of efficiency and volume in medium and high-power applications. For this reason, a common practice is to realize multiphase parallel connection on the PFC unit or DC-DC unit, which may reduce the stress of the device and the volume of the magnetic part. Thus, the efficiency and heat dissipation are improved, and meanwhile, input and output current ripples are reduced by utilizing interleaved control. Alternatively, the related technologies, such as employing interleaved PFC, employing coupled inductance, a DC-DC isolation transformer employing a matrix transformer, etc., are to some extent contribute to improving the efficiency and the power density, but they may not effectively reduce the volume of the magnetic part and the stress of the switching device, and may not achieve automatic current sharing, in which an additional current-sharing control is required to be added and a control complexity of a system is also increased.